Mucormycosis of the central airways: CT findings in three patients

Isolated tracheobronchial mucormycosis: report of a case and systematic review of literature

BACKGROUND

Isolated tracheobronchial mucormycosis (ITBM) is an uncommonly reported entity. Herein, we report a case of ITBM following coronavirus disease 2019 (COVID-19) and perform a systematic review of the literature.

CASE DESCRIPTION AND SYSTEMATIC REVIEW

A 45-year-old gentleman with poorly controlled diabetes mellitus presented with cough, streaky hemoptysis, and hoarseness of voice two weeks after mild COVID-19 illness. Computed tomography and flexible bronchoscopy suggested the presence of a tracheal mass, which was spontaneously expectorated. Histopathological examination of the mass confirmed invasive ITBM. The patient had complete clinical and radiological resolution with glycemic control, posaconazole, and inhaled amphotericin B (eight weeks). Our systematic review of the literature identified 25 additional cases of isolated airway invasive mucormycosis. The median age of the 26 subjects (58.3% men) was 46 years. Diabetes mellitus (79.2%) was the most common risk factor. Uncommon conditions such as anastomosis site mucormycosis (in 2 lung transplant recipients), post-viral illness (post-COVID-19 [n=3], and influenza [n=1]), and post-intubation mucormycosis (n=1) were noted in a few. Three patients died before treatment initiation. Systemic antifungals were used in most patients (commonly amphotericin B). Inhalation (5/26; 19.2%) or bronchoscopic instillation (1/26; 3.8%) of amphotericin B and surgery (6/26; 23.1%) were performed in some patients. The case-fatality rate was 50%, primarily attributed to massive hemoptysis.

CONCLUSION

Isolated tracheobronchial mucormycosis is a rare disease. Bronchoscopy helps in early diagnosis. Management with antifungals and control of risk factors is required since surgery may not be feasible.

Infections causing central airway obstruction: role of bronchoscopy in diagnosis and management

Central airway obstructive infections (CAOI) are challenging medical conditions that may represent an advanced and complicated process of ongoing infections. The epidemiology of CAOI is unknown as well as the pathophysiology and the mechanism of development. This is due to sparse data in the literature that consists mainly of case reports and retrospective case series. CAOI can be caused by fungal, bacterial, parasitic and viral infections. Most patients with CAOI can be diagnosed clinically and with chest imaging, which demonstrate obstruction of the central airways. However, bronchoscopy is commonly used to confirm and obtain a specific diagnosis to guide specific therapy. In recent years, interventional pulmonology (IP) is becoming widely available and offer a minimally invasive approach for the management of central airway diseases such as cancers, benign strictures, and other conditions. Various bronchoscopic modalities are used to treat central airway obstruction (CAO), such as mechanical debulking, endobronchial laser therapy, electrocautery, argon plasma coagulation, cryotherapy, and airway stenting. In patients with CAOI, the role of therapeutic bronchoscopy is not clearly defined, but many isolated reports in the literature described bronchoscopic intervention in combination with medical therapy as the initial management approach. In this paper, we present cases of CAOI that underwent bronchoscopic intervention as part of their management. We described the infectious etiology, locations, bronchoscopic findings and bronchoscopic modalities for airway management.

Endobronchial squamous cell carcinoma presenting as localized, long, continuous bronchial thickening on CT

OBJECTIVE

To report pulmonary squamous cell carcinomas presenting as localized, long, continuous, bronchial thickening on computed tomography (CT).

MATERIALS AND METHODS

This study comprised five men (mean age, 66 years; range, 60-79 years) with pulmonary squamous cell carcinoma, including two (0.6%) selected from 310 consecutive patients with the diagnosis. Inclusion criteria were as follows: histological diagnosis obtained from thickened bronchi; continuous bronchial thickening >5cm in longitudinal extension on CT. CT scans were retrospectively reviewed, focusing on bronchial abnormalities. They were correlated with histopathological findings in four patients who underwent lobectomy.

RESULTS

On initial CT, bronchial thickening was continuous without skip area (n=5), measured 56-114mm in maximum longitudinal length, involved lobar (n=3) or segmental and distal bronchi (n=5) of the right upper (n=4) or lower (n=1) lobe, and was focally bulbous (n=2). Follow-up CT before treatment, available in two, showed progression of bronchial thickening in its thickness and longitudinal length (n=2) and a new bulbous portion (n=1) and peribronchial nodules (n=1) along the thickened bronchi. Cancer recurred after lobectomy in two, one of which manifested as continuous bronchial thickening extending from the bronchial stump on CT. On CT-histopathological correlation, bronchial thickening was mostly due to tumor spreading along the bronchus. A focal or short segmental tumor outgrowth from the thickened bronchi corresponded to a nodule or bulbous portion along thickened bronchi on CT, respectively.

CONCLUSION

Pulmonary squamous cell carcinoma may present as localized, long, continuous, bronchial thickening on CT, simulating benign infectious or inflammatory diseases.

Imaging of Large Airways Disorders

OBJECTIVE

Recent technical advances, including the routine use of CT thin sections and techniques such as 2D minimum-intensity-projection and 3D volume images, have increased our ability to detect large airways diseases. Furthermore, dedicated CT protocols allow the evaluation of dynamic airway dysfunction.

CONCLUSION

With diseases of the large airways more commonly seen in daily practice, it is important that radiologists be familiar with the appearances, differential diagnosis, and clinical implications of these entities.

Predictors of pulmonary zygomycosis versus invasive pulmonary aspergillosis in patients with cancer

BACKGROUND

Pulmonary zygomycosis (PZ), an emerging mycosis among patients with cancer, has a clinical manifestation similar to that of invasive pulmonary aspergillosis (IPA). Most cases of PZ in such patients develop as breakthrough infections if treatment with antifungal agents effective against Aspergillus species is administered. However, clinical criteria to differentiate PZ from IPA are lacking.

METHODS

We retrospectively reviewed the clinical characteristics and computed tomography (CT) findings for 16 patients with cancer and PZ and for 29 contemporaneous patients with cancer and IPA at the time of infection onset (2002-2004). Patients with mixed infections were excluded. Parameters predictive of PZ by univariate analysis were included in a logistic regression model.

RESULTS

Almost all patients with PZ (15 of 16) and IPA (28 of 29) had underlying hematological malignancies and typical risk factors for invasive mold infections. In logistic regression analysis of clinical characteristics, concomitant sinusitis (odds ratio [OR], 25.7; 95% confidence interval [CI], 1.47-448.15; P = .026) and voriconazole prophylaxis (OR, 7.76; 95% CI, 1.32-45.53; P = .023) were significantly associated with PZ. The presence of multiple (> or = 10) nodules (OR, 19.8; 95% CI, 1.94-202.29; P = .012) and pleural effusion (OR, 5.07; 95% CI, 1.06-24.23; P = .042) at the time that the patient underwent the initial CT were both independent predictors of PZ in the logistic regression analysis of radiological parameters. No difference occurred in the frequency of other CT findings suggestive of pulmonary mold infections (e.g., masses, cavities, halo sign, or air-crescent sign) between the 2 patient groups.

CONCLUSIONS

PZ in immunocompromised patients with cancer could potentially be distinguished from IPA on the basis of clinical and radiological parameters; prospective validation is needed.